Monoidal Functors, Species and Hopf Algebras

Monoidal Functors, Species and Hopf Algebras
Author: Marcelo Aguiar
Publisher: American Mathematical Soc.
Total Pages: 784
Release: 2010
Genre: Mathematics
ISBN: 9780821847763

This research monograph integrates ideas from category theory, algebra and combinatorics. It is organized in three parts. Part I belongs to the realm of category theory. It reviews some of the foundational work of Benabou, Eilenberg, Kelly and Mac Lane on monoidal categories and of Joyal and Street on braided monoidal categories, and proceeds to study higher monoidal categories and higher monoidal functors. Special attention is devoted to the notion of a bilax monoidal functor which plays a central role in this work. Combinatorics and geometry are the theme of Part II. Joyal's species constitute a good framework for the study of algebraic structures associated to combinatorial objects. This part discusses the category of species focusing particularly on the Hopf monoids therein. The notion of a Hopf monoid in species parallels that of a Hopf algebra and reflects the manner in which combinatorial structures compose and decompose. Numerous examples of Hopf monoids are given in the text. These are constructed from combinatorial and geometric data and inspired by ideas of Rota and Tits' theory of Coxeter complexes. Part III is of an algebraic nature and shows how ideas in Parts I and II lead to a unified approach to Hopf algebras. The main step is the construction of Fock functors from species to graded vector spaces. These functors are bilax monoidal and thus translate Hopf monoids in species to graded Hopf algebras. This functorial construction of Hopf algebras encompasses both quantum groups and the Hopf algebras of recent prominence in the combinatorics literature. The monograph opens a vast new area of research. It is written with clarity and sufficient detail to make it accessible to advanced graduate students.

Hopf Algebras and Tensor Categories

Hopf Algebras and Tensor Categories
Author: Nicolás Andruskiewitsch
Publisher: American Mathematical Soc.
Total Pages: 347
Release: 2013-02-21
Genre: Mathematics
ISBN: 0821875647

This volume contains the proceedings of the Conference on Hopf Algebras and Tensor Categories, held July 4-8, 2011, at the University of Almeria, Almeria, Spain. The articles in this volume cover a wide variety of topics related to the theory of Hopf algebras and its connections to other areas of mathematics. In particular, this volume contains a survey covering aspects of the classification of fusion categories using Morita equivalence methods, a long comprehensive introduction to Hopf algebras in the category of species, and a summary of the status to date of the classification of Hopf algebras of dimensions up to 100. Among other topics discussed in this volume are a study of normalized class sum and generalized character table for semisimple Hopf algebras, a contribution to the classification program of finite dimensional pointed Hopf algebras, relations to the conjecture of De Concini, Kac, and Procesi on representations of quantum groups at roots of unity, a categorical approach to the Drinfeld double of a braided Hopf algebra via Hopf monads, an overview of Hom-Hopf algebras, and several discussions on the crossed product construction in different settings.

Hopf Algebras and Their Generalizations from a Category Theoretical Point of View

Hopf Algebras and Their Generalizations from a Category Theoretical Point of View
Author: Gabriella Böhm
Publisher: Springer
Total Pages: 171
Release: 2018-11-01
Genre: Mathematics
ISBN: 3319981374

These lecture notes provide a self-contained introduction to a wide range of generalizations of Hopf algebras. Multiplication of their modules is described by replacing the category of vector spaces with more general monoidal categories, thereby extending the range of applications. Since Sweedler's work in the 1960s, Hopf algebras have earned a noble place in the garden of mathematical structures. Their use is well accepted in fundamental areas such as algebraic geometry, representation theory, algebraic topology, and combinatorics. Now, similar to having moved from groups to groupoids, it is becoming clear that generalizations of Hopf algebras must also be considered. This book offers a unified description of Hopf algebras and their generalizations from a category theoretical point of view. The author applies the theory of liftings to Eilenberg–Moore categories to translate the axioms of each considered variant of a bialgebra (or Hopf algebra) to a bimonad (or Hopf monad) structure on a suitable functor. Covered structures include bialgebroids over arbitrary algebras, in particular weak bialgebras, and bimonoids in duoidal categories, such as bialgebras over commutative rings, semi-Hopf group algebras, small categories, and categories enriched in coalgebras. Graduate students and researchers in algebra and category theory will find this book particularly useful. Including a wide range of illustrative examples, numerous exercises, and completely worked solutions, it is suitable for self-study.

Classical Hopf Algebras and Their Applications

Classical Hopf Algebras and Their Applications
Author: Pierre Cartier
Publisher: Springer Nature
Total Pages: 277
Release: 2021-09-20
Genre: Mathematics
ISBN: 3030778452

This book is dedicated to the structure and combinatorics of classical Hopf algebras. Its main focus is on commutative and cocommutative Hopf algebras, such as algebras of representative functions on groups and enveloping algebras of Lie algebras, as explored in the works of Borel, Cartier, Hopf and others in the 1940s and 50s. The modern and systematic treatment uses the approach of natural operations, illuminating the structure of Hopf algebras by means of their endomorphisms and their combinatorics. Emphasizing notions such as pseudo-coproducts, characteristic endomorphisms, descent algebras and Lie idempotents, the text also covers the important case of enveloping algebras of pre-Lie algebras. A wide range of applications are surveyed, highlighting the main ideas and fundamental results. Suitable as a textbook for masters or doctoral level programs, this book will be of interest to algebraists and anyone working in one of the fields of application of Hopf algebras.

Hopf Algebras, Tensor Categories and Related Topics

Hopf Algebras, Tensor Categories and Related Topics
Author: Nicolás Andruskiewitsch
Publisher: American Mathematical Soc.
Total Pages: 359
Release: 2021-07-06
Genre: Education
ISBN: 1470456249

The articles highlight the latest advances and further research directions in a variety of subjects related to tensor categories and Hopf algebras. Primary topics discussed in the text include the classification of Hopf algebras, structures and actions of Hopf algebras, algebraic supergroups, representations of quantum groups, quasi-quantum groups, algebras in tensor categories, and the construction method of fusion categories.

Monoidal Categories and the Gerstenhaber Bracket in Hochschild Cohomology

Monoidal Categories and the Gerstenhaber Bracket in Hochschild Cohomology
Author: Reiner Hermann:
Publisher: American Mathematical Soc.
Total Pages: 158
Release: 2016-09-06
Genre: Mathematics
ISBN: 1470419955

In this monograph, the author extends S. Schwede's exact sequence interpretation of the Gerstenhaber bracket in Hochschild cohomology to certain exact and monoidal categories. Therefore the author establishes an explicit description of an isomorphism by A. Neeman and V. Retakh, which links Ext-groups with fundamental groups of categories of extensions and relies on expressing the fundamental group of a (small) category by means of the associated Quillen groupoid. As a main result, the author shows that his construction behaves well with respect to structure preserving functors between exact monoidal categories. The author uses his main result to conclude, that the graded Lie bracket in Hochschild cohomology is an invariant under Morita equivalence. For quasi-triangular bialgebras, he further determines a significant part of the Lie bracket's kernel, and thereby proves a conjecture by L. Menichi. Along the way, the author introduces n-extension closed and entirely extension closed subcategories of abelian categories, and studies some of their properties.

Bimonoids for Hyperplane Arrangements

Bimonoids for Hyperplane Arrangements
Author: Marcelo Aguiar
Publisher: Cambridge University Press
Total Pages: 853
Release: 2020-03-19
Genre: Mathematics
ISBN: 110849580X

The goal of this monograph is to develop Hopf theory in a new setting which features centrally a real hyperplane arrangement. The new theory is parallel to the classical theory of connected Hopf algebras, and relates to it when specialized to the braid arrangement. Joyal's theory of combinatorial species, ideas from Tits' theory of buildings, and Rota's work on incidence algebras inspire and find a common expression in this theory. The authors introduce notions of monoid, comonoid, bimonoid, and Lie monoid relative to a fixed hyperplane arrangement. They also construct universal bimonoids by using generalizations of the classical notions of shuffle and quasishuffle, and establish the Borel-Hopf, Poincar -Birkhoff-Witt, and Cartier-Milnor-Moore theorems in this setting. This monograph opens a vast new area of research. It will be of interest to students and researchers working in the areas of hyperplane arrangements, semigroup theory, Hopf algebras, algebraic Lie theory, operads, and category theory.

Symmetries of Algebras, Volume 1

Symmetries of Algebras, Volume 1
Author: Chelsea Walton
Publisher: 619 Wreath Publishing
Total Pages: 325
Release: 2024-07-08
Genre: Mathematics
ISBN: 1958469262

This is the first volume of a graduate-level textbook series in the area of Algebraic Quantum Symmetry. The focus of this book series is on how one can do abstract algebra in the setting of monoidal categories. It is intended for readers who are familiar with abstract vector spaces, groups, rings, and ideals, and the author takes care in introducing categorical concepts from scratch. This book series on Symmetries of Algebras is intended to serve as learning books to newcomers to the area of research, and a carefully curated list of additional textbooks and articles are featured at the end of each chapter for further exploration. There are also numerous exercises throughout the series, with close to 200 exercises in Volume 1 alone. If you enjoy algebra, and are curious about how it fits into a broader context, this is for you.

Quasi-Hopf Algebras

Quasi-Hopf Algebras
Author: Daniel Bulacu
Publisher: Cambridge University Press
Total Pages: 545
Release: 2019-02-21
Genre: Mathematics
ISBN: 1108427014

This self-contained book dedicated to Drinfeld's quasi-Hopf algebras takes the reader from the basics to the state of the art.

Homotopy of Operads and Grothendieck-Teichmuller Groups

Homotopy of Operads and Grothendieck-Teichmuller Groups
Author: Benoit Fresse
Publisher: American Mathematical Soc.
Total Pages: 581
Release: 2017-04-21
Genre: Mathematics
ISBN: 1470434814

The Grothendieck–Teichmüller group was defined by Drinfeld in quantum group theory with insights coming from the Grothendieck program in Galois theory. The ultimate goal of this book is to explain that this group has a topological interpretation as a group of homotopy automorphisms associated to the operad of little 2-discs, which is an object used to model commutative homotopy structures in topology. This volume gives a comprehensive survey on the algebraic aspects of this subject. The book explains the definition of an operad in a general context, reviews the definition of the little discs operads, and explains the definition of the Grothendieck–Teichmüller group from the viewpoint of the theory of operads. In the course of this study, the relationship between the little discs operads and the definition of universal operations associated to braided monoidal category structures is explained. Also provided is a comprehensive and self-contained survey of the applications of Hopf algebras to the definition of a rationalization process, the Malcev completion, for groups and groupoids. Most definitions are carefully reviewed in the book; it requires minimal prerequisites to be accessible to a broad readership of graduate students and researchers interested in the applications of operads.